For environmental, economic, and resource security reasons, there is a desire to obtain energy and material products from bio-renewable resources and particularly from “waste” and/or non-food biomass feedstocks. The various chemical components within typical biomass can be employed in a number of ways. For example, the cellulose and hemicellulose in plant matter may fermented into fuel grade alcohol, synthetic biodiesel, fuel grade butanol, xylitol, succinic acid, and other useful materials. The lignin component from biomass, and other types of extractives, have potential as a useful source of chemicals for certain industrial applications. Extracting these valuable resources from biomass could increase the commercial viability of the various biorefining/pulping processes. However, to date most biomass fractionation techniques employed by industry have been optimized for the production of high-quality fibre rather than the production of lignins and their derivatives. Thus, large-scale commercial application of the extractives, particularly those isolated in traditional pulping processes employed in the manufacture of pulp for paper production, has been limited due to, for example, the inconsistency of their chemical and functional properties. These inconsistencies may, for example, be due to changes in feedstock supplies and the particular extraction, generation, and/or recovery conditions. These issues are exacerbated by the complexity of the molecular structures of the extractives, such as lignin derivatives, produced by the various extraction methods and the difficulty in performing reliable routine analyses of the structural conformity and integrity of recovered extractives. Despite this lignin derivatives obtained via organosolv extraction, such as the Alcell® process (Alcell is a registered trademark of Lignol Innovations Ltd., Burnaby, BC, CA), have been used in rubber products, adhesives, resins, plastics, asphalt, cement, casting resins, agricultural products, oil-field products and as feedstocks for the production of fine chemicals.
Various processes are known for the biorefining of lignocellulosic feedstocks. These include, for example, ammonia pretreatment, dilute acid pretreatment, dilute ammonia pretreatment, concentrated acid hydrolysis, steam explosion, lime treatment, and the like. These treatment processes often produce a carbohydrate-rich stream which is frequently fermented into a biofuel such as biodiesel. These processes usually produce further chemicals such as lignin derivatives at the like. Additionally, these processes can leave a solid or semi-solid lignaceaus residue which may comprise lignins, recalcitrant cellulose, and other substances. This material is typically considered ‘waste’ and may be burnt for its fuel value.